F-15K fighter jets fly over Korea along with U.S. B-1B bombers and F-35B stealth fighters in a joint drill on Monday.

The joint show of force came after North Korea fired another mid-range ballistic missile over Japan last week.

At an event marking the F-35's 70th anniversary on Friday, Trump said, "Now, when our enemies hear the F-35 engines, when they're roaring overhead, their souls will tremble, and they'll know a day of reckoning is alive."

Defense Ministry officials here also told the National Assembly Defense Committee that a U.S. aircraft carrier strike group will participate in a joint drill in the Korean waters next month.

"It's unclear yet which U.S. aircraft carrier is coming -- the USS Ronald Reagan in Yokosuka, Japan or the USS Carl Vinson at the U.S. west coast," a government source here said.